Systems and methods for extending the fresh life of perishables in the retail and vending setting

ABSTRACT

The present disclosure relates to mechanically refrigerated retail and vending display systems and methods or use for extending the shelf-life of perishable products in the retail or vending setting. This is accomplished by maintaining an appropriate modified and controlled atmosphere (MA/CA) environment for the perishable product in a retail or vending display unit. The systems and methods of the invention maintain the MA/CA environment for a time period of 10 days or longer, wherein the marketable shelf-life of a perishable product is at least doubled. The systems may also operate in a power generation/power production mode, such that the fuel cells maintain the MA/CA environment while providing both primary and/or back-up power.

FIELD OF THE INVENTION

The invention relates to systems and methods for creating and maintaining modified and controlled atmospheres (MA/CA) in retail and vending systems used for the display and sale of perishable products. The systems and methods alter the natural gaseous environment around the perishable product such that the appearance and fresh shelf-life is extended.

BACKGROUND OF THE INVENTION

The consumer demand for fresh perishable products, such as food, and the desire to procure such products conveniently is increasing. Currently, modified atmosphere packaging (MAP) and freezing are used to extend the storage-life of perishable products by inhibition of spoilage organisms.

Respiring perishables are often stored in modified and controlled (“MA/CA”) atmospheres in order to maximize shelf life and “freshness”.

Modified Atmosphere Packaging (“MAP”) is the replacement of the normal atmospheric environment in storage packaging with a single gas or a mixture of gases. There are economic and global waste reduction incentives to eliminate MAP and MAP in the presence of vacuum (“MAP/VAC”) and the packaging machines and massive quantities of packaging materials currently employed to extend the shelf life of fresh and fresh cooked perishable products, including fresh seafood, meat, poultry, bakery goods, prepared meals and entrees and other non-respiring and respiring perishables.

The presence of oxygen at the levels typically found in ambient air cause changes in color and general appearance of perishables, in particular non-respiring perishables, resulting in a loss of quality.

The lack of refrigeration will also impact the quality and safety of perishables, in particular, non-respiring perishables, by allowing for the growth of aerobic spoilage microorganisms.

Freezing harms the appearance and palatability of perishable products, such as food, as well as consuming large amounts of energy both to freeze and maintain frozen temperatures. Frozen foods are also frequently packaged in costly and energy intensive packaging materials that also contribute to environmentally damaging global waste streams.

In addition, there is significant loss of perishables including fresh and fresh prepared perishables, such as fresh seafood, meat, poultry, bakery, prepared meals and entrees, frozen meals, entrees, and other non-respiring and respiring perishables due to spoilage, particularly at retail and vending and food service venues. Any food source that is perishable in air is vulnerable to spoilage and such fresh and natural pre-cooked (but not commercially sterile) foods are not safe to sell fresh in traditional low oxygen MAP/VAC formats.

There remains a need for methods and systems for the retail and vending display of perishable products, e.g., non-respiring fresh perishables (such as fresh fish) such that fresh food may be delivered to the consumer with more shelf life and in an environmentally sound and economically viable manner.

The present invention addresses this need.

BRIEF SUMMARY OF THE INVENTION

The invention provides methods and systems for generating and maintaining a modified and controlled atmosphere (MA/CA) environment for extending the fresh shelf-life of perishable products in a refrigerated retail or vending display system, which includes a sealable, mechanically refrigerated retail or vending display unit having at least one refrigeration component, at least one sealable gas port and an oxygen reduction means.

Operation of the mechanical refrigeration unit generates a recirculating, forced gas stream that can be directed across the oxygen reduction means for efficiently providing and maintaining a low oxygen modified and controlled atmosphere (MA/CA) environment in the retail or vending display unit wherein the fresh shelf-life of one or more perishable products in the retail or vending display unit is at least twice as long as that of the same perishable products not maintained in an MA/CA environment.

Exemplary perishable products are non-respiring fresh perishables selected from the group consisting of meat, fish, poultry, bakery and dairy.

The MA/CA environment for non-respiring fresh perishables comprises an oxygen level of 10000 ppm or less and a CO₂ level of 25-100%, a temperature within the range of 26° F.-37° F. and a humidity level of greater than 75%, e.g., 75%-100%, 75%-80%, 80% to 85%, 85% to 90%, 90-95%, 90%-98% or 100%.

The retail or vending display unit holds from 3 days to 21 days of inventory and the marketable shelf-life of the non-respiring fresh perishable products in the unit is least doubled.

The retail or vending display system may comprise one or more of a: (a) means for loading or unloading the retail or vending display unit while minimizing the amount of ambient air that enters the MA/CA environment of the primary unit; (b) sensing, control and user-interface means effective to manage and maintain the conditions of the primary high CO₂, low O₂, temperature-controlled MA/CA environment; (c) sensing, control and user-interface means that manage one or more of loading, selecting, unloading, product rotation, centrally controlled and programmed digital pricing and promotional displays, packaging, mitigating and communicating anomalies; and (d) a temporary storage or inventory unit.

The low O₂ MA/CA environment in the retail or vending display system is established and maintained by an oxygen reduction means selected from the group consisting of electrochemical means, catalytic means, chemical or biochemical means, mechanical means, pressure swing, or a combination thereof.

The oxygen reduction means may be an electrochemical fuel cell configured to generate power. When the mechanical refrigeration unit is in the power production mode, the unit is effective to operate for charging system backup batteries for operating in the absence of an external power source, maintaining operation of the refrigeration unit to provide temperature control and/or to maintain the specified MA/CA conditions in the retail or vending display unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary sealable refrigerated retail display with dual use fuel cells and below floor inventory.

FIG. 2 depicts an exemplary retail display refrigeration unit with fuel cell/generator plenum assembly.

FIG. 3 depicts an exemplary retail MA/CA fresh seafood and meat display.

FIG. 4 depicts a conventional refrigerated vending machine.

FIG. 5 depicts an exemplary refrigerated vending machine.

FIG. 6 depicts a side/see-through view of an exemplary refrigerated vending machine.

FIGS. 7 a and b depict examples of vending embodiments, including an exemplary MA/CA respiring perishables vending system (FIG. 7 a), and a MA/CA fresh and prepared meal vending system (FIG. 7 b).

DETAILED DESCRIPTION OF THE INVENTION

All patents, publications, and patent applications cited in this specification are herein incorporated by reference as if each individual patent, publication, or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes.

Introduction.

The present invention is directed to methods and systems for generating and maintaining modified and controlled atmosphere (MA/CA) environments in mechanically refrigerated retail and vending display systems in order to enhance the shelf life of perishable goods and reduce related carbon footprints and waste streams.

Definitions.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although other methods and materials similar, or equivalent, to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.

In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.

As used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.

The term, “perishable product” refers to a product, e.g., food that is capable of spoiling microbiologically and oxidatively.

The term, “non-respiring perishables” is used herein with reference to meat, fish, poultry, bakery, dairy and the like.

The term, “respiring perishables” is used herein with reference to fruit, vegetables, flowers, plants, whole, precut or prepared.

The term, “retail or vending system” is used interchangeably herein with the term “retail or vending display”, with reference to display of products for sale to companies and end user consumers. An effective retail or vending display presents products in a manner that they are accessible and attractive to merchandizers and consumers.

The term, “shelf-life” is used herein with reference to the recommended time that a product can be stored, during which the defined quality of a specified proportion of the goods remains acceptable under expected (or specified) conditions of distribution, storage and display. Most shelf life dates are used as guidelines based on normal and expected handling and exposure to temperature.

The term, “marketable shelf-life” is used herein with reference to the length of time a perishable product is given before they are considered unsuitable for sale, use, or consumption.

The term, “factors that shorten marketable shelf-life” is used herein with reference to sensory changes perceived by the consumer such as appearance, color, odor, texture and taste, which render the product unsuitable for sale, use, or consumption.

As used herein the term “mechanical refrigeration system”, is used with reference to a system (container, room, etc.) that includes means for removing unwanted heat with discharge to another location. Mechanical refrigeration means include, but are not limited to fluorocarbon, ammonia, CO2, cryogenic and other refrigerant/refrigeration systems.

As used herein the term, “modified atmosphere” means a retail or vending display environment that has been modified from ambient conditions in terms of temperature, humidity, percentage of oxygen (O₂), percentage of carbon dioxide (CO₂), percentage of nitrogen (N₂) and other non-ambient atmosphere components.

As used herein the term, “controlled atmosphere” is used with reference to a retail or vending display environment for perishables in which oxygen, carbon dioxide, and nitrogen concentrations, as well as temperature and humidity are regulated.

As used herein the term, “modified and controlled atmosphere (MA/CA) environment” for non-respiring perishables is used herein with reference to an MA/CA environment comprising an oxygen level of 10000 ppm or less and a CO₂ level of 25-100%.

As used herein the term, “oxygen reduction means” is used with reference to any device that can function to reduce oxygen levels in a refrigerated, high CO₂ closed environment.

As used herein the term, “low oxygen environment”, “low 0₂ environment”, “low oxygen level”, and “low O₂ level”, with respect to an MA/CA environment for non-respiring perishables means the O₂ level is maintained at 10000 ppm or less, 9000 ppm or less, 8000 ppm or less, 7000 ppm or less, 6000 ppm or less, 5000 ppm or less, 4000 ppm or less, 3000 ppm or less, 2000 ppm or less or 1000 ppm or less.

As used herein the term, “reducing oxygen to near zero levels” means the percentage oxygen is close to 0%, e.g., less than 0.1% (1000 ppm), less than 0.05% (500 ppm) or less than 0.01% (100 ppm).

As used herein the term, “high carbon dioxide environment”, “high CO₂ environment” “high carbon dioxide level”, and “hi CO₂ level”, with respect to an MA/CA environment for non-respiring perishables means the CO₂ level is maintained at a level from about 25% to 100%, for example, greater than 25%, greater than 30%, greater than 35%, greater than 40%, greater than 45%, greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, greater than 98% or greater than 99%.

As used herein the term, “high CO₂ environment” with respect to an MA/CA for non-respiring perishables means the CO₂ level is maintained at 25%-100%.

For respiring fresh perishables, the MA/CA environment has a CO₂ level maintained at less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, or less than 1% CO₂.

As used herein the term, “continuous flushing” means adding gas (e.g., CO₂), with a continuous flow rate into the system at about the same rate or about 50%, about 25%, about 12.5%, or about 6.25% or about 3.12%, or about 1.56% higher than the flow rate of gas (e.g., CO₂), out of the system.

As used herein the term, “oxygen reduction means” is used with reference to any device that can function to reduce oxygen levels in a refrigerated, high CO₂ closed environment.

As used herein, a “fuel cell” consists of an anode (negative side), a cathode (positive side) and an electrolyte that allows charges to move between the two sides of the fuel cell. At the anode a catalyst oxidizes the fuel, usually hydrogen, turning the fuel into a positively charged ion and a negatively charged electron. The electrolyte is a substance specifically designed for ions to pass through it, while the electrons cannot. The free electrons travel through a wire creating an electric current. The ions travel through the electrolyte to the cathode. Upon reaching the cathode, the ions are reunited with the electrons and the two react with a third chemical, usually oxygen, to create water. Unlike batteries, fuel cells do not run down and they do not require recharging.

As used herein the terms, “single slice fuel cell architecture”, and “slice fuel cell architecture” are used with reference to the unstacked configuration of hydrogen fuel cells that are integrated into or adapted to the refrigerated MA/CA system or mechanical refrigeration unit of the invention. An alternate configuration would be “stacked” instead of “single slice” where the several single slice fuel cells are joined together in a stacked configuration.

As used herein the term, “PEM fuel cell architecture” is used with reference to a fuel cell that comprises a proton exchange membrane (“PEM”), also known as a polymer electrolyte membrane.

Overview

The present invention relates to sealable mechanically refrigerated units for retail and vending display of perishable products. The sealable mechanically refrigerated retail or vending display units have at least one refrigeration component, at least one sealable gas port and an oxygen reduction means.

Operation of the mechanical refrigeration units generates a low oxygen modified and controlled atmosphere (MA/CA) environment in the retail or vending display such that the fresh shelf-life of one or more perishable products present in the retail or vending display is at least twice as long as the fresh shelf-life of the same perishable products which have not been maintained in an MA/CA retail or vending display environment.

In a preferred embodiment, operation of the mechanical refrigeration unit generates a recirculating, forced gas stream that can be directed across said oxygen reduction means wherein the oxygen reduction means is more effective to reduce and maintain the oxygen level inside the retail or vending display unit at a level of 10000 ppm or less in a high CO₂ environment.

The mechanically refrigerated retail or vending display unit can maintain the MA/CA environmental conditions for at least 3 days and for 20 days or longer such that oxidatively-degradable perishable products stored in the MA/CA retail or vending display maintain quality and freshness for at least twice as long as oxidatively-degradable perishable products stored outside the MA/CA environment.

The mechanically refrigerated retail and vending display systems of the invention provide a modified and controlled atmosphere (MA/CA) environment for periods of time greater than 3 days, and up to at least 20 days. The time period during which the MA/CA environment is maintained is at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 21 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days, or at least 20 days.

The time period during which the MA/CA environment is maintained in the retail or vending display unit is impacted by the leak-tightness of the retail or vending unit, the control features that establish and maintain the specified MA/CA environment such as hydrogen or other fuel cell reactant and the amount of supplemental CO₂, N₂ or other gasses available for maintaining a neutral to slight positive pressure inside the unit.

The leak tightness of the retail or vending display units disclosed herein and the ability to maintain the specified MA/CA conditions for at least 20 days provides substantial advantages over existing retail or vending display systems, most of which are open to the ambient air. Accordingly, currently available systems result in significant waste both in terms of refrigeration energy losses to ambient, excess packaging expense and waste and spoilage losses due to short shelf life and perishability.

FIG. 1 depicts an example of a sealable refrigerated retail display with dual use fuel cells and below floor inventory. The figure shows the covered/sealed display section 100, inventory 101, a fuel cell plate/plenum positioned over retail or vending refrigeration unit air/gas intake 102, an air plenum for power generation 103, the retail or vending store floor 104, a vacuum pump 105, a hydrogen (H₂) cylinder 106, a carbon dioxide (CO₂) cylinder 107, a CALL 108 and a CAUL 109.

FIG. 2 depicts an exemplary retail or vending display refrigeration unit with fuel cell/generator plenum assembly. The figure shows the retail or vending display refrigeration unit 200 fuel cells 203 and the plenum assembly shown together with an air driven generator 201 used to charge MA/CA system batteries 202. The fuel cell plenum 204 is attached over the air intake. FIG. 3 depicts an exemplary retail or vending MA/CA fresh seafood and meat display.

FIG. 4 depicts a conventional refrigerated vending machine, indicating air intake 400, a refrigeration unit 401, air delivery 402, the refrigerated section 403 and a dispenser 404. FIG. 5 depicts an exemplary refrigerated vending machine, indicating an outside air plenum with sealable cathode ports (for dual use fuel cells) 500, a fuel cell plenum air intake with O-ring cathode seals in oxygen reduction position over air intake 501, a refrigeration unit 502, air delivery 503, the sealable refrigerated MA/CA section 504, a partially closed primary MA/CA dispensing CAUL slide valve 505, a CAUL dispenser 506, a CO₂ storage and dispensing vessel 507, and a vacuum pump 508. FIG. 6 depicts a refrigerated vending machine, indicating controls and communications 300, a sealable access loading door 301, and hydrogen storage and plumbing to the fuel cell plenum 302. FIGS. 7 a and b depict an exemplary MA/CA respiring perishables vending system (FIG. 7 a), and a MA/CA fresh and prepared meal vending system (FIG. 7 b).

MA/CA Environments for Non-Respiring Perishables

The environmental conditions for optimizing the shelf life of non-respiring fresh perishables are very different from the conditions for extending the shelf life of respiring perishables.

In a preferred embodiment, the invention includes retail and vending display systems that provide optimal conditions for non-respiring fresh perishables, e.g., any raw or precooked perishable, including seafood, meat, poultry, bakery goods, precooked entrees and meals, case-ready meats and the like. The mechanically refrigerated MA/CA retail and vending display systems are effective to at least double the shelf-life of non-respiring fresh perishables when maintained in the MA/CA retail or vending display.

In one preferred embodiment, the mechanically refrigerated MA/CA retail and vending display systems and methods for their use provide a preferred MA/CA environment for non-respiring fresh perishables that is an ultra-low (to zero) oxygen (O₂) and high carbon dioxide (CO₂) environment.

The temperature in a MA/CA environment for non-respiring fresh perishables is generally in a range of 26-37° F., e.g., 26-27° F., 27-30° F., 28-31° F., 29-32° F., 30-31° F., 30-32° F., 30-33° F., 31-33° F., 31-34° F., 32-35° F., 33-35° F. or 35-37° F., typically within the range of 26-32° F.

The preferred oxygen percentage in a MA/CA retail or vending display environment for non-respiring fresh perishables is from about 0.01% to about 1% (about 100 to 10,000 ppm), preferably 10,000 ppm (1%) or less, 9000 ppm (0.9%) or less, 8000 ppm (0.98%) or less, 7000 ppm (0.7%) or less, 6000 ppm (0.6%) or less, 5000 ppm (0.5%) or less, 4000 ppm (0.4%) or less, 3000 ppm (0.3%) or less, 2000 ppm (0.2%) or less, 1000 ppm (0.1%) or less, 800 ppm (0.08%) or less, 600 ppm (0.06%) or less, 400 ppm (0.04%) or less, 200 ppm (0.02%) or less, or 100 ppm (0.01%) or less.

A preferred MA/CA environment for retail or vending display of non-respiring fresh perishables typically includes high or elevated carbon dioxide (CO₂), and typically contains mixtures of nitrogen (N₂), oxygen (O₂) and CO₂.

For respiring fresh perishables, an MA/CA environment has a CO₂ level maintained at less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, or less than 1% CO₂.

The mechanically refrigerated retail and vending display systems of the invention are capable of maintaining a high CO₂ MA/CA environment without continuous “flushing” of CO₂, however; in some situations, gas injection or flushing may be employed to create a desired gaseous mixture in the CA/MA environment of the retail or vending display, e.g., by injection or flushing with an alternative gas, such as CO₂, or alternatively a gas mixture. Gas flushing may be employed through one or more sealable valves for flushing air out of the retail or vending display system.

MA/CA Environments for Respiring Perishables

In one embodiment, the invention provides mechanically refrigerated retail or vending display systems designed to provide appropriate conditions for respiring fresh perishables; fruit, vegetables, flowers, plants; whole, precut and/or prepared.

A preferred oxygen range for respiring perishables is from about 0% to about 21%, typically above 1% (10,000 ppm) and the CO₂ level is preferably below 25% and may be as low as 0%.

The preferred temperature in a mechanically refrigerated retail or vending display environment for respiring fresh perishables is generally in a range of 32-37° F. In a preferred MA/CA environment, the temperature range is 32-34° F., however the temperature range can be much higher in the case of some respiring perishables (e.g., bananas in the 50° F. to 60° F. range).

Oxygen Reduction Means

The mechanically refrigerated retail or vending display units of the invention may rely on any oxygen reduction means capable of reducing oxygen (O₂) to near zero levels in a high CO₂ MA/CA environment.

The oxygen reduction means is any device that can function in a refrigerated, high CO₂ environment, for example, electrochemical means (e.g., fuel cells), chemical scavengers, pressure swing devices, catalysts and the like effective to reduce oxygen levels below 0.1% (1000 ppm or less) in high CO₂ environments as quickly as possible, for example, within 72 hours or less of sealing the unit.

The oxygen reduction means is effective to reduce the oxygen level inside the retail or vending display unit to 10000 ppm or less, 9000 ppm or less, 8000 ppm or less, 7000 ppm or less, 6000 ppm or less, 5000 ppm or less, 4000 ppm or less, 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, 500 ppm or less, or 100 ppm or less in 72 hours or less.

In a preferred embodiment, the oxygen reduction means is effective to reduce and maintain the oxygen level for at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 7 days, at least 8 days, at least 9 days, at least 10 days, at least 11 days, at least 12 days, at least 13 days, at least 21 days, at least 15 days, at least 16 days, at least 17 days, at least 18 days, at least 19 days or for at least 21 days or longer with replenished hydrogen and CO2.

Air flow in the retail or vending display is dependent upon the refrigeration unit with the air flow rate dictated by the capacity and size of refrigeration unit. The flow rate of the forced air stream must be sufficient for the oxygen reduction means to function such that oxygen is reduced to low levels within 72 hours or less from sealing said perishable in display.

The oxygen reduction means may cease to operate when the oxygen level in a sealable retail or vending display unit of the invention reaches and is maintained below a predetermined level, e.g., 10000 ppm or less, 9000 ppm or less, 8000 ppm or less, 7000 ppm or less, 6000 ppm or less, 5000 ppm or less, 4000 ppm or less, 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, 500 ppm or less, or 100 ppm or less.

In one preferred embodiment, the oxygen reduction means is a hydrogen-powered fuel cell which provides for oxygen reduction, as well as sensing and control means necessary to maintain the MA/CA environment.

Fuel Cells

Embodiments of the retail and vending display systems disclosed herein may be powered entirely by fuel cell technologies. In a preferred embodiment, a retail or vending display system of the invention comprises one or more fuel cells integrated into or adapted to the refrigerated MA/CA system or refrigeration unit of the system.

In one preferred embodiment of the invention, the fuel cells are one or more hydrogen fuel cells comprising an anode and a cathode wherein the recirculating, forced MA/CA stream generated by operation of the refrigeration unit is directed across the fuel cell cathode such that oxygen is reacted with hydrogen ions to form water, heat and electricity inside the retail or vending display unit. The anode of the one or more fuel cells is in communication with a hydrogen source.

In a preferred embodiment of the invention, one or more single slice hydrogen powered fuel cells are strategically distributed across the refrigerated air intake or air delivery means of the mechanical refrigeration unit to optimally expose the fuel cell cathode to the recirculating atmosphere.

The hydrogen powered fuel cells do not require venting of oxygen to the exterior of the retail or vending unit and are adaptable to existing sealable retail or vending display systems and newly built systems.

The fuel cells are typically single slice fuel cells, and may comprise a proton exchange membrane, also known as a polymer electrolyte membrane or “PEM”. One example of a PEM is a perfluorinated ion-exchange membrane, e.g., a “Nafion” (DuPont) membrane.

The most common type of hydrogen fuel cell architecture known in the art provides a stack orientation of individual fuel cells. It is generally understood by those of skill in the art that the stack orientation of hydrogen fuel cells is a more cost effective way to generate power, than hydrogen fuel cell architecture which provides individual fuel cells in a slice orientation.

In a preferred embodiment of the invention, multiple single slice fuel cells are strategically distributed across refrigerated air intake or air delivery means of the mechanical refrigeration system. In other embodiments, one or more hydrogen fuel cells may be provided in stack architecture or a combination of slice and stack architecture.

Prior art fuel cell systems for power generation in the context of refrigeration (e.g., U.S. Pat. No. 6,179,986), employ stack fuel cell architecture running in reverse (electrolysis) mode which does not integrate the fuel cells into the existing refrigeration system. U.S. Pat. No. 6,179,986 therefore does not offer the synergies of the strategically distributed integrated fuel cells of the retail and vending display systems disclosed herein. In addition, the system described in U.S. Pat. No. 6,179,986 would not be practical in the context of the transportation and storage systems described herein because U.S. Pat. No. 6,179,986 requires too much power and is extremely complex, including venting of oxygen to the exterior of the container or storage environment and complex air filtering, gas liquid separation and management of water.

In one embodiment, the fuel cell apparatus is designed to provide power production and oxygen reduction at the same time (as further detailed herein).

Other fuel cell types that can be used in practicing the invention include a SOFC (Solid Oxide Fuel Cell), a MCFC (Molten Carbonate Fuel Cell), an AFC (Alkaline Fuel Cell), or a PAFC (Phosphoric Acid Fuel Cell).

Hydrogen for use in the fuel cells of the invention may be stored in uncompressed or compressed gas or liquid form adjacent to or internal to the MA/CA retail or vending unit, for example hydrogen may be stored in gaseous form in low or high-pressure vessels or as solid state or in liquid (cryogenic) tanks. Uncompressed H₂ is defined as <40 PSI.

Vacuum or Modified Atmosphere Packaging (MAP/VAC).

A beneficial MAP environment for most packaged retail and vending products need only extend freshness to the point of being opened, given that the contents are typically consumed shortly thereafter. In such cases, the short shelf life available after opening the package is not an issue and typical MAP or MAP/VAC packaging is sufficient. However, fresh seafood and preservative-free fresh cooked foods and meals are not safe in low oxygen MAP/VAC packaging if the appropriate temperature is not maintained.

Therefore, in order to safely and economically offer these high value perishables in retail or vending display settings, the MA/CA environmental and refrigerated temperature requirements are much more stringent to preserve these fresh perishable products. Without conventional MAP/VAC packaging most fresh and fresh prepared perishables, such as fresh seafood, meat, poultry, bakery goods, prepared meals and entrees, frozen meals, and other non-respiring and respiring fresh perishables are susceptible to rapid microbial spoilage and oxidative deterioration.

MAP/VAC packaging machines and massive quantities of packaging materials are currently employed to extend the shelf life of those fresh perishables that are food safe under poor or no refrigeration.

Conventional low oxygen MAP/CAP/VAC (e.g. vacuum “Cryovac” packaging) has worked reasonably well for many primal and sub-primal cuts of fresh meat due to the fact that the meat is further trimmed and freshly cut for retail and vending and food service sale after removal from the bulk MAP/CAP/VAC environment. In addition, there are no regulated food safety issues with fresh (non-seafood and uncooked) meat, poultry and other bulk perishables packaged, stored or transported in MAP/CAP/VAC environments.

In contrast, conventional low oxygen MAP/VAC packaging has not been effective or safe for non-respiring fresh perishables such as preservative-free, fresh seafood (e.g., sushi), pre-cooked meals and entrees due to the potential for temperature fluctuations of improperly refrigerated packages. These perishable products, when packaged in ultra-low oxygen environments can become unsafe if the appropriate temperature is not maintained and can be lethal if consumed raw or inadequately cooked (e.g., due to C. botulinum growth).

Absorption of CO₂ by virtually all proteins is one reason conventional MAP/VAC cannot achieve the shelf life facilitated by the retail and vending display methods and systems disclosed herein, particularly the shelf life remaining after removal from the MA/CA environment. The full range of atmosphere modification and control enabled by this invention is not possible in conventional MAP. Consequently, perishable products provided in the retail or vending display units disclosed herein will display fresher characteristics and longer shelf life after removal from the claimed MA/CA systems relative to similar perishables not maintained in a MA/CA retail or vending display environment.

The inventions herein solve this problem by integrating oxygen reduction means and ultra-low oxygen environments into mechanical, constantly and consistently refrigerated retail or vending display systems for food-safe and cost effective freshness extensions of respiring and non-respiring fresh perishables.

CALL Controlled Atmosphere (CA) Loading Lock “CALL”

Preferred embodiments include novel CA Unloading Locks (CAUL) and methods for managing removal/dispensing of perishable products from the retail or vending display units without disturbing the primary display or inventory MA/CA environments.

This serves to prevent reductions in the extended fresh shelf-life for the perishables remaining in the established MA/CA retail or vending display environment.

In some situations, a vacuum is applied to the CAUL in combination with CO₂ injection to rapidly achieve the required high CO₂, low O₂ MA/CA environment prior to dispensing a non-respiring perishable.

In some embodiments, the methods and systems further comprise a controlled atmosphere (CA) loading lock or “CALL” useful to transfer a fresh perishable product from ambient air into the retail or vending display unit. A CALL maintains the conditions of the requisite high CO₂, low O₂ and temperature-controlled MA/CA environment of retail or vending display unit. In other situations, an oxygen reduction means is also applied to the CALL to achieve the required high CO₂, low O₂ MA/CA environment.

The CALL may be designed to accommodate vacuum levels necessary to accelerate the removal of trapped oxygen from perishables (e.g. ground beef or bakery goods) and related packaging, without damaging the perishable.

The vacuum can optionally be created passively by the selective removal of oxygen from the initial air contained in the CALL or actively by mechanical means, such as vacuum pumps. The CALL optionally contains selective oxygen reduction means, preferably hydrogen powered fuel cell(s) with plumbing means, valves and controls (as further detailed above) to provide hydrogen and maintain fuel cell operation, including anode purging cycles as required.

Optional embodiments include means for introducing CO₂, N₂ and other volatiles and dispersibles into the CALL as additional or alternate preconditioning methods and processes. In preferred embodiments the retail or vending display unit also contains oxygen reduction means (preferably hydrogen fed fuel cells) along with means for introducing CO₂, N₂ and other volatiles and dispersibles (e.g., humidity, ozone, MCP).

The CALL may function to pre-condition and deoxygenate a perishable product before gaseous communication with the retail or vending display MA/CA environment. These features reduce undesired degradation of the primary MA/CA environment by air, trapped air and oxygen and air-borne environmental components when adding or removing perishable products from the MA/CA retail or vending display environment.

A CALL may optionally include gas injection and/or gas flushing means. Gas flushing with any non-oxygen (or low oxygen) gas or gas mixture can be employed to deoxygenate the CALL without vacuum.

A CALL chamber optionally contains conveying means such that perishable products can be automatically moved into and out of the MA/CA retail or vending display unit. Conveying means comprise any automated, mechanical or manual means known in the art for moving perishable products into or out of the CALL chamber.

Other embodiments comprise manual conveyance means that enable periodic perishable product loading, selecting and unloading.

Preferred embodiments include novel logic, MA/CA components and controls necessary for automatic mitigation and communication of anomalies that might compromise food safety or perishable marketability in retail and vending display applications of MA/CA environments for perishables. These features are designed to avoid/minimize loss of perishable value in the event of any system failure by automatically optimizing environmental components to prevent complete loss of perishable and to provide additional time for additional mitigation measures that can enable full value capture.

Optional sensing and control means manage all or part of the retail or vending display unit environment and processes including loading, selecting, unloading/dispensing, product rotation, digital pricing and promotional displays, packaging, and the like.

Controlled Atmosphere Unloading Lock (“CAUL”)

Typically, a sealable CA Unloading Lock (CAUL) is also employed. In preferred embodiments, a sealable CAUL contains an automatically actuated and sealable entry door or closure between the retail or vending display unit and the CAUL. This door or closure is optionally open during normal operation when no unloading activities are being conducted to allow the CAUL to be in constant atmosphere equilibration with the primary retail or vending display unit.

If the CAUL is not equilibrated with the retail or vending display unit, the entry door must remain sealed and the CAUL atmosphere sufficiently modified before opening the unloading door to the MA/CA retail or vending display unit.

After a perishable product is transferred into the CAUL, the sealable unloading door between the primary MA/CA unit and the CAUL is closed followed by opening a sealable exit/unloading/dispensing door or closure that is normally closed and sealed to exclude entry of ambient air into the CAUL.

In some preferred embodiments, CA Unloading Locks (CAUL) are employed to facilitate dispensing or removal of perishable units from a retail or vending display unit. Removal of perishables from the retail or vending display unit may be optionally sequenced through a CAUL.

After a perishable unit is transferred into the CAUL, the sealable unloading door is closed followed by opening a sealable exit/unloading/dispensing door or closure that is normally closed and sealed to exclude entry of ambient air into the CAUL, so that the perishable can be removed into ambient conditions.

After removal/conveyance of the perishable from the CAUL, entry and exit doors are closed to prevent entry of additional ambient air and the remaining air in the CAUL is deoxygenated by an oxygen reduction means or flushed with non-oxygen gas before reopening the entry door to the primary chamber.

The CAUL optionally includes external gas injection and flushing means. Gas flushing means may include a sealable valve(s) for flushing air out of CAUL chamber with an alternative gas or gas mixture.

A CALL or CAUL chamber may optionally be vented with air or other gas before exiting to air or another treatment chamber to dilute non-air gaseous and dispersible components. Examples of this embodiment include the use of carbon monoxide in the CA atmosphere or the need to vent CO₂ or ozone from the chamber to prevent exposure of personnel.

A CALL or CAUL chamber may include a refrigeration unit, which may optionally have oxygen reduction means integrated into or adapted to the refrigeration unit as disclosed above.

The CALL and CAUL may be combined for dual function.

A CAUL or primary MA/CA display system may also optionally include packaging/wrapping, weighing and labeling means for perishables portions being removed from the retail or vending display unit.

The CALL or CAUL chamber size is dictated by the range of unit sizes to be handled by the chamber and may be as small as smallest retail or vending display packages. Perishable product units can be loaded by any feasible means into a “CA lock”.

Retail and Vending Display Units

The retail and vending display systems disclosed herein provide advantages that safely prolong the shelf-life of fresh perishable products. The retail and vending display systems generally include one or more of a refrigerated retail or vending display unit with temperature monitoring and control, oxygen monitoring and control, carbon dioxide monitoring and control, optional humidity monitoring and control, inventory capability, automated rotation, digital pricing and promotional displays, packaging, and automated labeling and dispensing of fresh perishable products.

In some embodiments, the fuel cells are internal to the retail or vending display unit. In other embodiments, the fuel cells are external to the retail or vending display unit, but in gaseous communication with the primary refrigerated MA/CA environment.

The retail and vending display systems comprise a modified and controlled atmosphere that is specifically designed with respect to oxygen, carbon dioxide, and nitrogen concentration, as well as temperature, humidity and positive pressure, in order to preserve the fresh shelf-life of the perishable product being displayed in the retail or vending unit.

Preferred embodiments include fully automated system controls for continuous self-monitoring, logging and communicating status alerts. System controls also facilitate automatic selection and delivery of proper service parameters for different perishables, “fool proof” self-diagnostics, automated initial MA servicing, continuous maintenance and analyses of critical MA/CA and refrigerated environment variables for anomaly forecasting and automated mitigation functions, including alerts and alarms optionally communicated wirelessly that collectively minimize losses due to various system malfunctions. Local or cloud-based databases retain all relevant information for data communication and mining. Such system controls may be present in the retail or vending display unit, CALL or CAUL.

Preferred embodiments include previously disclosed novel logic, MA/CA components and controls necessary for automatic mitigation and communication of anomalies that might compromise food safety or perishable marketability in retail or vending display applications of MA/CA environments for perishables. These features are designed to avoid/minimize loss of perishable value in the event of any system failure by automatically optimizing environmental components to prevent complete loss of perishable and to provide additional time for additional mitigation measures that can enable full value capture.

Retail and vending display units of the invention may include any functional configuration that serves to display perishable products and can accommodate the MA/CA environment disclosed herein. The retail or vending display unit must be substantially sealable and airtight to exclude the unintentional ingress of outside air, and may be oriented in a vertical, horizontal, stacked or connected manner.

The MA/CA retail and vending display units disclosed herein enable reduced spoilage losses with longer food-safe shelf life together with the possibility for extended retail and vending display, inventory, automated rotation, digital pricing and promotional displays, sale selection, packaging, labeling and dispensing of fresh perishable products.

In one embodiment, the retail or vending display provides individual perishable portions. The MA/CA system will substantially eliminate spoilage losses at the retail or vending level, where these losses are highest and most costly.

The enclosed/sealed design of the retail or vending display system allows the user to create and maintain the required MA/CA environment, while significantly reducing energy losses common to currently available open refrigerated retail or vending displays.

The enclosed design also enhances food safety and sanitation by protecting the perishable products from handling and associated operator contamination (e.g., from sneezing), and the like.

The display systems will track and rotate perishables based on information systems that automatically track remaining shelf life based on the input of traceability information and continuously updated perishables shelf life data and related knowledge bases.

Automatic (digitally displayed) pricing for each perishable product portion can be centrally controlled, including promotional information, price reductions to move expiring product and electronic inventory control, restocking, new orders with complete product traceability information available for each and every perishable product portion and sale. Data can be maintained indefinitely and may be useful to track any latent issues and to build useful marketing and sales information.

Retail or vending display units may be designed to be cost effectively replenished once a week (or less frequently) reducing labor involved in resetting fresh counters and rewrapping fresh seafood and other highly perishable foods.

The retail or vending display units may optionally include CIP (Clean-In-Place) capabilities for automated wash down and sanitation of all food contact surfaces in the display unit.

Power Generation

In one aspect, the invention provides for optional power generation by the fuel cells which also serve as the oxygen reduction means in a refrigerated retail or vending display system of the invention.

When the fuel cells of the mechanically refrigerated system are in the power generation/power production mode, the fuel cells can provide power for charging system batteries that may provide both primary and back-up power for refrigeration and/or the MA/CA systems.

The mechanically refrigerated systems of the invention may be capable of operation in a power production mode while maintaining the desired gaseous component mixture in the modified atmosphere environment of the retail or vending display system, e.g., high CO₂/low O₂ for retail or vending display of non-respiring fresh perishables.

In one embodiment of the invention, the fuel cell apparatus is designed to allow for some or all of the cathodes to be exposed to outside air while still maintaining the desired internal modified atmosphere. This embodiment allows for power production (instead of oxygen reduction) and can be automatically controlled as necessary for both oxygen reduction and power production. It will be understood that in this embodiment, the mechanical refrigeration unit of the retail or vending display system can provide power production and oxygen reduction at the same time.

An exemplary fuel cell mounting plate/plenum design that can switch between recirculating oxygen reduction function to air (or oxygen) circulation across fuel cells for power production without compromising the low O₂, high CO₂ atmosphere, comprises a plenum containing sealable ports for the cathode plates of single slice fuel cell(s) and a two position valve.

When the oxygen level in the retail or vending display is reduced to 10,000 ppm or less, most of the fuel cell cathodes may be redirected to receive air or oxygen for power production while one or more fuel cells remain in the oxygen reduction configuration for maintaining the oxygen level at 10,000 ppm or less (higher for respiring perishables).

Oxygen reducing fuel cells may be configured to provide power for refrigeration and additional MA/CA systems and/or battery charging capabilities potentially enabling more reliable, lower power refrigeration systems for the retail or vending display of chilled perishables without the need for expensive add-on generators during periods of unavailable line power.

Preferred embodiments also include retail and vending display systems with refrigeration air flow powered generators to keep MA/CA system batteries charged during low oxygen (non-power generating) conditions without the need for any hard wire connections, maintaining all control options, including mitigation and communication functions regardless of refrigeration system power status and enhancing reliability of the retail or vending display system.

When a retail or vending display system of the invention is in a power-generating mode, a fuel source for supplying hydrogen necessary for electrochemical oxygen reduction means is provided, e.g., uncompressed or compressed H₂ or another source of hydrogen such as methane, LNG, KOH, water or another suitable electrochemical fuel and the power to convert or generate hydrogen from the respective source.

Utility

The invention serves to provide extended shelf life for fresh, perishable products in a retail or vending display setting that are safe and appealing to the consumer or other end user.

The methods and processes of the invention enable food-safe and sustainable inventorying, retail and vending display and sale of perishable products that are vulnerable to decreased quality when stored in an ambient air environment. The claimed retail or vending display systems have an MA/CA environment tailored to the perishable products stored therein and effective to extend the shelf-life during and after removal from the MA/CA retail or vending display unit. The display may have different CA zones that comprise different levels of oxygen, CO₂ and other atmosphere components tailored for the predominant perishable contained in a given zone.

The invention finds utility in extended shelf life and reducing spoilage losses at the retail and vending display level for all fresh and fresh prepared perishables, providing a more sustainable fresh food supply.

Fresh and fresh prepared perishables that are perishable in ambient air are often frozen, acidified, or otherwise made safe by using preservatives or thermal processes that harm the appearance and palatability of the food, as well as consuming large amounts of energy and including the production of vast amounts of energy intensive packaging materials and environmentally damaging waste.

The retail or vending display units of the invention can replace this costly packaging and may be designed to be cost effectively replenished once a week (or less frequently), reducing labor involved in resetting fresh counters, packaging and repackaging costs and related waste associated with conventional fresh seafood displays.

The retail or vending display units find utility in any setting where fresh perishables foods are provided, for example, in company cafeterias, on military ships, in remote installations, on cruise ships and other remote feeding locations.

The use of hydrogen-based (“clean”) oxygen reduction and power generation systems is a clean and sustainable benefit of the retail and vending display systems disclosed herein.

The claimed retail and vending display systems also eliminate the need for energy intensive freezing of perishable foods that are either not safe to market fresh by currently available means or too perishable for economies of scale, or simply less profitable frozen as compared to the retail and vending display systems disclosed herein.

The retail and vending display systems of the invention also enable applications of the most powerful MA/CA environments for perishables categories that are difficult to package due to the fragility or porosity of the perishable itself (e.g., bakery and floral products).

The retail and vending display systems disclosed herein also provide a venue for new, more palatable fresh prepared convenience food categories, for example; fresh, preservative-free, pre-cooked meals and entrees with greatly extended shelf life that can leverage economies of scale and cost-effective retail and vending sales. These fresh and natural pre-cooked (but not commercially sterile) foods are not safe to sell fresh in traditional low oxygen MAP/VAC formats.

In one particularly valuable use of the invention, the economic and sustainability benefit to a retail and vending provider of the most cost effective solution(s) for extending the freshness of seafood are substantial. For example, a 2009 USDA report measured an average of 8% spoilage losses at retail and vending fresh seafood and meat counters. This costs all stakeholders in global fresh food value chains billions of dollars annually. 

It is claimed:
 1. A method for extending the fresh shelf-life of perishable products in a refrigerated retail or vending display system, comprising: (a) obtaining one or more perishable products; (b) providing a sealable, mechanically refrigerated retail or vending display unit having at least one refrigeration component, at least one sealable gas port and an oxygen reduction means; and (c) transferring the one or more perishable products to the retail or vending display unit, wherein operation of said mechanical refrigeration unit generates a recirculating, gaseous forced air stream that can be directed across the oxygen reduction means creating and maintaining a low oxygen modified and controlled atmosphere (MA/CA) environment in said retail or vending display unit wherein the fresh shelf-life of one or more perishable products is at least twice as long as that of the same perishable products not maintained in an MA/CA environment.
 2. The method of claim 1, wherein said one or more perishable products are non-respiring fresh perishables selected from the group consisting of meat, fish, poultry, bakery and dairy.
 3. The method of claim 2, wherein said MA/CA environment comprises an oxygen level of 10000 ppm or less and a CO₂ level of 25-100%.
 4. The method of claim 3, wherein said MA/CA environment comprises an oxygen level of 9000 ppm or less, 8000 ppm or less, 7000 ppm or less, 6000 ppm or less, 5000 ppm or less, 4000 ppm or less, 3000 ppm or less, 2000 ppm or less 1000 ppm or less, 500 ppm or less, or 100 ppm or less.
 5. The method of claim 3, wherein said MA/CA environment comprises a CO₂ level of greater than 25%, greater than 30%, greater than 35%, greater than 40%, greater than 45%, greater than 50%, greater than 55%, greater than 60%, greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, greater than 98% or greater than 99%.
 6. The method of claim 3, wherein said MA/CA environment further comprises a temperature within the range of 26° F.-37° F. and a humidity level selected from the group consisting of greater than 75%, 75%-100%, 75%-80%, 80% to 85%, 85% to 90%, 90-95%, 90%-98% and 100%.
 7. The method of claim 1, wherein said retail or vending display unit holds from 3 days to 21 days of inventory, wherein the marketable shelf-life of the non-respiring fresh perishable products is at least doubled.
 8. The method of claim 1, wherein said retail or vending display unit comprises a means for loading or unloading the retail or vending display unit while minimizing the amount of ambient air that enters the MA/CA environment of the retail or vending display.
 9. The method of claim 1, wherein the sealable retail or vending display unit comprises sensing, control and user-interface means effective to manage and maintain the conditions of the primary high CO₂, low O₂, temperature-controlled MA/CA environment.
 10. The method of claim 1, wherein the retail or vending display unit further comprises sensing, control and user-interface means that manage one or more of loading, weighing, selecting, unloading, product rotation, centrally controlled and programmed digital pricing and promotional displays, packaging, mitigating and communicating anomalies.
 11. The method of claim 1, wherein said low O₂ MA/CA environment is established and maintained by an oxygen reduction means selected from the group consisting of electrochemical means, catalytic means, chemical or biochemical means, mechanical means, pressure swing, or a combination thereof.
 12. The method of claim 1, wherein said retail or vending display system further comprises a temporary storage or inventory unit.
 13. The method of claim 12, wherein said temporary storage or inventory unit provides for perishable product storage used to replenish the retail or vending display unit as product is removed from the retail or vending display.
 14. The method of claim 11, wherein said oxygen reduction means is a fuel cell effective to generate power.
 15. The method of claim 14, wherein the power-generating fuel cell compromises a switchable fuel cell cathode exposable to a recirculating stream inside the sealable retail or vending display unit and to air or another oxygen source contained inside or outside said sealable retail or vending display unit.
 16. The method of claim 14, wherein when said mechanical refrigeration unit is in the power production mode, the unit is effective to operate in the absence of an external power source and maintain operation of the refrigeration unit to provide temperature control and to maintain the specified MA/CA conditions in the retail or vending display unit.
 17. The method of claim 14, wherein when said mechanical refrigeration unit is in the power production mode, the unit is effective to charge one or more batteries.
 18. A retail or vending display system for extending the shelf-life of a perishable product, including a mechanically refrigerated sealable retail or vending display unit, comprising: (a) a refrigeration component having at least one sealable gas port wherein operation of said mechanical refrigeration unit generates a recirculating, gaseous forced air stream; (b) an oxygen (O₂) reduction means wherein the O₂ reduction means provides and maintains a low oxygen modified and controlled atmosphere (MA/CA) environment in the retail or vending display unit; (c) a carbon dioxide (CO₂) input means wherein the CO₂ input means provides and maintains a high CO₂ modified and controlled atmosphere (MA/CA) environment in the retail or vending display unit: and (d) one or more perishable products located in the modified and controlled atmosphere (MA/CA) environment of the retail or vending display unit, wherein said MA/CA environment is maintained in the refrigerated sealable retail or vending display unit and the marketable shelf-life of perishable products stored in said unit is least doubled as compared to the shelf-life of a perishable product stored in a retail or vending display wherein said MA/CA environment is not maintained.
 19. The retail or vending display system of claim 18, wherein said perishable product is a non-respiring fresh perishable selected from the group consisting of fresh or precooked meat, fish, poultry, bakery and dairy.
 20. The retail or vending display system of claim 18, wherein said MA/CA environment comprises an oxygen level of 10000 ppm or less, a CO₂ level of 25-100% and a humidity level selected from the group consisting of greater than 75%, 75%-100%, 75%-80%, 80% to 85%, 85% to 90%, 90-95%, 90%-98% and 100%. 